Tap.



v UNITED I srn r ng P E T ornron.

THOMAS F. KEAN, OF BOSTON, MASSACHUSETTS.

TAP.-

provement in expanding taps forcutting the threads in nuts; and it has for its objects to provide new and improved means whereby as-soon. as the thread has been cut in the nut the cutters are automatically withdrawn from engagement with the nut andthe nut can be quickly and easily removed without reversing its spiral'movement or unscrewing it from the cutters, whereby this automatic release of the nut by thewithdrawal of the cutters is accomplished when the tapping process reaches a predetermined point, and whereby in other respects the tap 1s rendered.

' more e'l'licient and its operation is facilitated;

The. nature of the invention is fully described below and illustrated in the accom-n panyin g drawings, in Which I Figure 1 is a plan .view of my improved tap with the cutters expanded into the. po

sition for cutting ascrew-thread in anut. Fig; 2 1s a horizontal sectlon of the same.

Fig. 3 is a longitudinal vertical section illustrating theposition of the parts whenjthe cone is thrown back by the spring and the cutters are thus. withdrawn sul'liciently to allow the-nut to be removed. Fig. 4 is a sect1on taken on line 4 4, Fig. 2.

Similar letters of reference indicate corresponding parts.

a. represents a cylindrical head provided with a back I), which is integral with the tail or shank c,'whereby the device may be aplied to or inserted in the turret of a turretathe. A front plate (I is screwed at c to the front edge of the cylindrical head a. Supported centrally at its opposite ends in the front plate (1 and back I) is a stud g, which supports slidingly a cone or frustum h.-

Thiscone is provided on its front ed e with a deep annular groove h, in which islocated a spiral spring 7c. The peripheral surface oi the cone is provided with radial dovetail grooves l of even depth throughout, and the cylindrical head a is provided with longitudinal radial slots m opposite or registering with the dovetail grooves Z and of even thickness and length therewith. Within these slots m and extending downinto the Specification of Letters Pa'tent, Application filed May 7, 1906. Serial No. 315.706.-

of which Patented Dec. ethane.

Inasmuch asthe dovetail grooves in the head renders the tap. expansive and contractive regardsits cutters. 1

The cone h is provided with two rearward parallel extensions 7),Figs. 1 and 3, which project through suitable openings in the rear wall I) along and parallel with opposite sides of the shank or tail 0. 1

1) represents a sliding carrier-arm whose -hub p is slidingly supported by the shank c, saidarm being prevented from rotation by the rod r, which extends through it from the head. This arm is bored to receive a rod 1, which constitutes a portion of a latch-comprising. said rod 1', threaded to receive a nut r, and a frame consisting of the tubular portion 8 in line with the rodr and the tubular portion 8 at right angles therewith, the portions '1", s, and 8 being one integral piece. The tubular portion 8 contains a bolt it, provided at its inner end with an integral hook or catch of and centrally with a horizontal opening "0, beveled at its r ear edge, as shown in Fig. 2, and the tubular portion 8 is pro' vided with a bolt w, slotted at w to receive the pin 15, extending from the portion s and beveled at its inner end to correspond with. the beveled rear edge of the opening v. A spring f holds the beveled portion of the opening against the beveled end of the bolt '21), and the pin t in the slot w ill iits the move ment of thebolt it. A horizontal plate j, re-

to the head. A yoke-lever w is pivotally secured at 00'' to a post 2'", extending horizontally from the rear side of the head a, and this yoke-lever is provided with two projections y, whereby it may beswung by its handle g cone are of'even depth throughout and as rocation of the cone horizontally within the m and the front plate d; but their dovetailed connection with the 'cone h is a sliding one;

TOO

ces'sed. at y" to receive the catch 'u",.is bolted ITO . position for operating on the nut;

against the flanged portions 22 of the hub p, and thus move said hub 111d. carrier-arm toward the head and the extensions i into the head for the purpose below described,

The normal position of the tap is that illustrated in Figs. 1, 2, and 4, in which the yokelever a; y has by means of its projections which bear on the flanges p", forced the hub p of the carrier-arm p toward the rear wall I) of the cylindrical head a, said hub 19 forcing in the extensions 5, and thus moving the cone h toward the front plate d against the power of the spring h, as shown in Fig. 2. At the same time the carrier-arm 1), moving with its hub p, moves the latch mechanism forward into locked engagement with the recessed plate j j, asindicated in Figs. 1 and 2. This forward movement of the cone it forces the cutters a radially outward to their fullest extent, thus expanding the tap into proper I The nut is moved up to the tap in the well-known manner and rotated, as usual, for the purpose of being tapped, and when during the tapping process the rotating nut reaches the outer end of'the bolt to, it pushes it in, withdrawing the catch it of the bolt a from the recessed plate 7' j, and the spring is instantly forces the cone it back into the position indicated in Fig. 3, and the extensions p force the hub p and its arm p-a distance beyond the back plate (Z which is equal to the distance moved by the cone, said hub also swinging the yoke-lever w 'y in the same direction. As the cone was thrown back by the spring Ir, it necessarily withdrew the cutters n wholly or partially into the grooves m, as above described, thus leaying the nut entirely out of engagement with the cutters n d free to be removed instantly without reversing its movement or imparting any rotation to it, saving, therefore, the time spent on reversing and unscrewing nuts from taps after they have been operated on. To relace the tap in operative position, the yokeever is swung forward, carrying with it the hub and carrier-arm p p, the extension i, and the latch mechanism, thus locking the latch mechanism and moving the cone into the position indicated in Fig. 2, and the cutters outward into expanded position ready for use. I

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. In a tap of the character described, a head or case, a cone adapted to slide in said head, an extension connected with the cone and projecting through a wall of the head, cutters extending through the )eripheral wall of the head and adapted to be moved outward or expanded by the forward movement of the cone, a latch mechanism adapted to be released at a predetermined point by the nut as it is being operated on by the cutters, a spring intermediate of the cone and the front wall or plate of the head, and mechanism intermediate of the latch mechanism and the cone whereby said cone is held normally forward by the latch mechanism against the power of the spring and released and thrown back when the latch mechanism is thrown out of engagement by the nut.

2. In a tap of the character,described,a head or case provided wit a suitable tailor shank, a conical cutter-holder adapted to slide in said head, cutters connected with said holder and extending through the head and adapted to be expanded by the forward movement of the cutter-holder, a spring normally compressed between the cutter-holder and front plate of the head, extensions connected with the cutter-holder and projecting through the rear wall of the head along, the shank, a latch mechanism in the path of the nut it is being operated'on, mechanism slidingly supported bysaid shank in the path of said extensions and directly supporting the-latch mechanism, and mechanism pivotally connected with the head and adapted to engage the mechanism in the path of the extensions and supporting the latch mechanism, for the purpose of returning simultaneously the cutter-holder and the latch mechanism into their original positions. I

- 3. In a tap of the character described, a head or case provided with a suitable tail or shank, a conical cutter-holder adapted to slide in said head,- cutters connected with said holder and extending through the head and adapted to be expanded by theforward movement of the cutter-holder, a spring normally compressed between the cutter-holder and front plate of the head, extensions connected with the cutter-holder and projecting through the rear wall of the head along the shank, a latch mechanism in the ath of the nut as it is being operated on, a anged hub adapted to slide on the shank-and with a carrier-arm for supporting t e latch mechanism, and a yoke-lever pivotally'sustained by the head and adapted to move the flanged carrier-arm hub into engagement with the extensions from the conical cutterholder and to yield when the latch is unlocked and the cutter-holder released and thrown back by the spring.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS F. KEAN.

Witnesses: I IIENRY W. WILLIAMS, A. K. H001).

rovided 

